Missile umbilical ignition switch



March 16, 1965 F. L. HAAKE 3,174,006

MISSILE UMBILICAL IGNITION SWITCH Filed April 30, 1962 39 36 so ,I 40

2 r K .2: 38 5 1 2e '48 4 3 INVENTOR.

. FREDERICK L. HAAKE F g. 4 BY United States Patent 3,174,006 MISSILE UMBILICAL IGNITION SWITCH Frederick L. Haake, 1519 Little Farms Road, Oxnard, Calif. Filed Apr. 30, 1962, Ser. No. 191,380 1 Claim. (Cl. 200-61.19) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The invention relates to electrical switches and more particularly to such a switch having a member providing a positive separation of the respective electrical contacts, the member being displaceable to permit closing of the contacts.

In the firing of a missile from its launcher, an umbilical plug assembly is utilized to maintain electrical continuity for various purposes with the launching station, whether it be on the ground or various types of vehicles, until separation at the point of launch. The switch controlling the firing of the missile can be operated manually, such as by a conventional lanyard or the firing switch can be mounted in a separate umbilical plug.

Where the firing circuit is housed in the launcher along with the power source, the firing switch circuit included one of the prongs of the umbilical half on the launcher and firing had to be initiated before umbilical disconnect. The disadvantage of such an arrangement, particularly where the launcher was on an aircraft, is obvious since accidental firing could occur while the missile was still on its launcher.

The present invention provides a firing switch which can be incorporated in an umbilical connector half, and which is energized only after umbilical disconnection thereby positively preventing accidental firing of a missile while on its launcher. The novel firing switch includes a pair of spring-biased contacts which are held in an open position, deenergizing the firing circuit, by an insulated plunger maintained in the umbilical plug by the presence of the missile on its launcher. After the umbilical plug is separated at the initial launch phase, the insulated plunger is ejected from the umbilical plug allowing the contacts to close and energizing the firing circuit to fire the missile.

One important object of this invention is to provide a firing switch that enables the firing circuit to be mounted in a missile.

Another important object is to provide a firing switch that can be incorporated into an umbilical plug, and which switch will remain in a deenerg-ized condition positively until the umbilical connector halves are separated.

A further object is to provide a firing switch that will prevent accidental firing of a missile until after launching from its launcher.

Still another object is to provide a firing switch the operation of which will not be affected by accidental damage to the umbilical prongs.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a front elevation view of one half of an umbilical plug mounted in a missile;

FIG. 2 is a longitudinal section taken along line IIII of FIG. 1 showing the connected umbilical halves on the missile and launcher;

FIG. 3 is an enlarged end view of the missile firing switch; and

dfl'ldfififi Patented Mar. 16, 1965 FIG. 4 is a longitudinal section taken along line IV- IV of FIG. 3 with some of the elements only partially crosssectioned.

Referring to the drawing where like reference numbers refer to similar parts throughout the figures there is shown in FIGS. 1 and 2 an umbilical plug half 10 mounted in a missile 12 such that the face 14 of the plug is flush with the missile skin 16. Umbilical plug half 10 may have potted therein a plurality of electrical connector halves 18, 20, 22, and 24 adapted to mate with corresponding connector halves, not shown, mounted in the other half of the umbilical plug 26 in the launcher 28. Connectors 18 to 24 connect various conventional circuits between the missile and launching station and need not be described. The novel firing switch 30 of this invention can be mounted concentrically within plug 24.

As shown in detail in FIGS. 3 and 4, firing switch 30 comprises a longitudinal tubular casing 32 constructed of insulation material having a core opening 34. A pair of spaced metal cylindrical plug-like contacts 36 and 38 are cemented within casing opening 34 by an epoxy adhesive, or otherwise secured therein contacts 36 and 38 are connected by conductors 37 and 39 respectively to a firing circuit, not shown, in the missile which may incorporate a condenser-pulse-type ignition (not shown). Casing 32 may be slotted at 41 to accommodate condoctor 37. A movable contact 40 backed by a compression coil spring 42 are both disposed in the casing between fixed contacts 36 and 38, contact 40 being normally biased by the spring to abut the fixed cont-act 36. Fixed contact 36 has an inner bevelled concave face 44 adapted to seat a corresponding convex face 45 on movable contact 40. A central drilled opening 46 and recessed end portion 43 of fixed contact 36 house a plunger 50 and an enlarged head portion 52, respectively. Plunger 50 is longer than the length of opening 46 for a purpose to be presently described. Piston 50 is made of insulating material, much as micarta, and when fully housed within the casing by engagement with the missile launcher the length of the plunger is sufficient to compress spring 42 and maintain contacts 36 and 40 in spaced relation and out of engagement to open the firing circuit.

When missile 12 is dropped or otherwise separated from the launcher the umbilical plugs 10 and 26 are separated and plunger 50 is no longer restrained by the launcher umbilical plug and is free to be ejected from the casing by the force of spring 42 which causes movable contact 4tl to electrically engage fixed contact 36. Electrical continuity is now complete between fixed con tacts 36 and 38 through spring 42 and movable cont-act 4910 close the firing circuit.

The firing switch is designed to be capable of being incorporated within an umbilical plug to simplify construction. Use of the insulated plunger positively maintains the missile firing circuit in an open condition until after separation of the missile and launcher preventing accidental firing of the missile while still on the launcher. Also the present invention enables a condenser-puise-type ignition package to be mounted in the missile avoiding the need to rely on a power source in the launcher for firing. Operation of the switch by the insulation plunger avoids reliance on a direct mechanical friction connection between the umbilical halves, thus accidental damage to the umbilical halves during launch will not adversely affect missile firing.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claim the invention may be practiced otherwise than as specifically described.

Iclaim:

A firing control device for a missile incorporating a firing circuit, said missile having a skin adapted to slide on a launcher during the launching operation, said control device comprising:

(a) an umbilical plug mounted entirely Within the skin of said missile;

(b) said missile having a longitudinal axis;

(c) a missile firing switch supported within said plug;

(d) said firing switch including a tubular housing made of insulation material oriented in a position substantially normal to said missile axis;

(6) said housing having an open end adjacent the missile skin;

(1) a pair of complementary conical-shaped electrical contacts supported in said housing in spaced relation, one of said contacts being movable;

(g) spring means within said housing and biasing said contacts into engagement;

(11) said plug contacts being connected by conductors to said firing circuit;

(1) one of said conical contacts being fixed Within the housing at the open end;

(j) said fixed contact having a central opening;

(k) an insulated plunger having one end portion freely slidably mounted in the central opening of said fixed contact and maintaining s aid movable contact out of engagement with the fixed plug by compressing the spring means;

(l) the other end of said insulated plunger being positioned in the open end of the housing and abutting the launcher;

whereby movement of the missile away from the launcher will free the insulated plunger permit-ting the spring means to completely eject such plunger from the plug and permit the said spring means to bring the two electrical contacts into engagement with one another, thereby closing said firing circuit.

References Cited by the Examiner UNITED STATES PATENTS 25 BERNARD A. GTLHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

